"Out, out, brief candle! Life's but a walking shadow": 5-HTTLPR Is Associated With Current Suicidal Ideation but Not With Previous Suicide Attempts and Interacts With Recent Relationship Problems

Genetic Variants Associated with Suicide Risk in the Mexican Population: A Systematic Literature Review

Suicide is defined as the action of harming oneself with the intention of dying. It is estimated that worldwide, one person dies by suicide every 40 s, making it a major health problem. Studies in families have suggested that suicide has a genetic component, so the search for genetic variants associated with suicidal behavior could be useful as potential biomarkers to identify people at risk of suicide. In Mexico, some studies of gene variants related to neurotransmission and other important pathways have been carried out and potential association of variants located in the following genes has been suggested: SLC6A4, SAT-1, TPH-2, ANKK1, GSHR, SCARA50, RGS10, STK33, COMT, and FKBP5. This systematic review shows the genetic studies conducted on the Mexican population. This article contributes by compiling the existing information on genetic variants and genes associated with suicidal behavior, in the future could be used as potential biomarkers to identify people at risk of suicide.

Testing the role of inflammation in the relation of childhood maltreatment and suicidal ideation among young adults

BACKGROUND

In recent years, the prevalence of suicidal ideation among young adults has been on the rise, with childhood maltreatment thought to partially explain this disparity. Systemic inflammation-a product of over-activation of the body's stress response system-has been hypothesized to play a predictive role in the development of suicidal ideation. Enduring childhood maltreatment can lead to systemic inflammation, possibly accounting for suicidal ideation's increased prevalence among young adults who have a history of childhood maltreatment.

METHODS

The current study sought to investigate the importance of childhood maltreatment as a static risk factor for downstream suicidal ideation in young adulthood with the immunological response (i.e., systemic inflammation) to childhood maltreatment serving as a mediating factor.

RESULTS

Systemic inflammation was found to be positively associated with suicidal ideation, supporting the unique role systemic inflammation may play in the pathogenesis of suicidal ideation, though hypotheses regarding childhood maltreatment were not supported.

CONCLUSION

This study provides novel insight into a potential immunobiological model for suicidal ideation development in young adult populations.

Usual presence and intensity of pain are differentially associated with suicidality across chronic pain conditions: A population-based study

OBJECTIVES

This study examined the prevalence of suicidality and associations with pain characteristics (i.e., presence of usual pain/discomfort, pain intensity) among those with chronic pain conditions (i.e., arthritis, migraine, back pain).

METHODS

We analyzed data from the 2012 Canadian Community Health Survey-Mental Health supplement (N = 25,113), including self-reported pain characteristics and suicidality. Weighted cross-tabulations described suicidality prevalence estimates according to pain characteristics among each chronic pain condition. Multiple logistic regressions evaluated associations between the presence of usual pain/discomfort and suicidality across pain conditions. Post-hoc analyses examined pain intensity in significant associations.

RESULTS

Across pain conditions, rates of suicidality were greater in those usually in pain and with more severe pain, compared to mild or moderate pain. After adjustment, usual pain/discomfort was associated with increased odds of suicide ideation (AOR = 1.79, 95% CI [1.19-2.68], p < .05) and attempts (AOR = 2.49, 95% CI [1.25-4.98], p < .05) among those with migraines, and plans (AOR = 1.55, 95% CI [1.04-2.31], p < .05) in those with back pain (reference = absence of usual pain). Usual pain/discomfort was not associated with suicidality in those with arthritis after adjusting for sociodemographics and psychiatric comorbidity. Post-hoc analyses showed that severe pain was associated with elevated odds of suicide ideation (AOR = 2.19, 95% CI [1.07-4.48], p < .05) in migraines and plans (AOR = 3.11, 95% CI [1.42-6.80], p < .01) in back pain (reference = mild pain).

CONCLUSION

Our findings may facilitate a more targeted approach to screening for suicidality among chronic pain populations.

Inflamed Mind: Multiple Genetic Variants of IL6 Influence Suicide Risk Phenotypes in Interaction With Early and Recent Adversities in a Linkage Disequilibrium-Based Clumping Analysis

Background: Understanding and predicting suicide remains a challenge, and a recent paradigm shift regarding the complex relationship between the immune system and the brain brought attention to the involvement of inflammation in neuropsychiatric conditions including suicide. Among cytokines, IL-6 has been most frequently implicated in suicide, yet only a few candidate gene studies and without considering the effect of stress investigated the role of IL6 in suicidal behaviour. Our study aimed to investigate the association of IL6 variation with a linkage disequilibrium-based clumping method in interaction with childhood adversities and recent stress on manifestations along the suicide spectrum. Methods: One thousand seven hundred and sixty-two participants provided information on previous suicide attempts, current suicidal ideation, thoughts of death, and hopelessness, and were genotyped for 186 variants in IL6. Early childhood adversities were recorded with an instrument adapted from the Childhood Trauma Questionnaire, recent life events were registered using the List of Threatening Life Events. Following a 3-step quality control, logistic and linear regression models were run to explore the effect of genotype and gene-environment interactions on suicide phenotypes. All regression models were followed by a clumping process based on empirical estimates of linkage disequilibrium between clumps of intercorrelated SNPs. Interaction effects of distinct types of recent life events were also analysed. Results: No clumps with significant main effects emerged, but we identified several clumps significantly interacting with childhood adversities on lifetime suicide attempts, current suicidal ideation, and current thoughts of death. We also identified clumps significantly interacting with recent negative life events on current suicidal ideation. We reported no clumps with significant effect on hopelessness either as a main effect or in interaction with childhood adversities or recent stress. Conclusion: We identified variant clumps in IL6 influencing suicidal behaviour, but only in interaction with childhood or recent adversities. Our results may bring us a step further in understanding the role of neuroinflammation and specifically of IL-6 in suicide, towards identifying novel biological markers of suicidal behaviour especially in those exposed to stressful experiences, and to fostering the adaptation of a new paradigm and identifying novel approaches and targets in the treatment of suicidal behaviour.